British Rail Class 21

British Rail Class 21 was a class of 1000hp or 1100hp Bo-Bo diesel-electric locomotives built by North British Locomotive Company in Glasgow. 58 were built nos D6100-D6157, and they were originally allocated to the Eastern Region for commuter services into London. Unfortunately, they proved to be extremely unreliable, and were quickly transferred to the Scottish Region for convenience of return to their manufacturer when warranty work was required. However, North British Loco closed down soon afterwards. In an attempt to improve reliability, 20 (D6100-03/06-08/12-14/16/19/21/23/24/29/30/33/34/37) were later re-engined with 1350hp Paxman engines to form Class 29. The remaining 38 locomotives retained their original MAN engines and were all withdrawn from service by the end of 1967. None have been preserved.

These locos should not be confused with the new Class 21s recently imported by EWS.

British Rail non-steam locomotives
Diesel locomotives - Electric locomotives - DMU - DEMU - AC EMU - DC EMU - Departmental units
	Diesel shunting locomotives
Classes:	01 - 01/5 - 02 - 03 - 04 - 05 - 06 - 07 - 08 - 09 - 10 - 11 - 12 - 13 - 14
Pre-TOPS type:	D1/1 - D1/2 - D1/3 - D1/4 - D2/1 - D2/2 - D2/3 - D2/4 - D2/5 - D2/6 - D2/7 - D2/8 - D2/9 - D2/10 - D2/11 - D2/12 - D3/1 - D3/2 - D3/3 - D3/4 - D3/5 - D3/6 - D3/7 - D3/8 - D3/9 - D3/10 - D3/11 - D3/12 - D3/13 - D3/14
Pre-1955 type:	11001 - 11104 - 15107 - 13000
	Main-line diesel locomotives
Classes:	15 - 16 - 17 - 20 - 21 - 21 (Vossloh) - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 33 - 35 - 37 - 40 - 41 (Warship Class) - 41 (HST) - 42 - 43 (Warship Class) - 43 (HST) - 44 - 45 - 46 47 - 48 - 50 - 52 - 53 - 55 - 56 - 57 - 58 - 59 - 60 - 66 - 67
Pre-TOPS type:	D8/1 - D8/2 - D10/1 - D10/2 - D10/3 - D11/1 - D11/2 - D11/3 - D11/4 - D11/5 - D12/1 - D12/2 - D12/3 - D13/1 - D14/1 - D14/2 - D15/1 - D15/2 - D16/1 - D16/2 - D17/1 - D17/2 - D20/1 - D20/2 - D22/1 - D22/2 - D23/1 - D25/1 - D27/1 - D33/1 - KA - KB
Pre-1955 type:	10000-10001 - 10100 - 10201-10203 - 10800
	Electric locomotives
Classes:	70 - 71 - 73 - 74 - 76 - 77 - 80 - 81 - 82 - 83 - 84 - 85 - 86 - 87 - 89 - 90 - 91 - 92
Pre-TOPS type:	AL1 - AL2 - AL3 - AL4 - AL5 - AL6 - EB1 - EE1 - EM1 - EM2 - ES1 - HA - HB - JA - JB
	Other locomotives
Departmental:	97 - 97/6 - Eastern - Southern - Other Series
Other:	98 - 99 - 15097-15099 - 18000 - 18100
Demonstrators:	D0226/D0227 - D0260 - D0280 - D9998 - DHP1 - DP1 - DP2 - GT3 - HS4000 - Janus/Taurus